Foreign Device Interface (FDI) devices such as accounting terminals and vend card devices were introduced on copiers many years ago. At that time, FDI devices were only used to control access to copying machines and to gather copy-related accounting data. FDI devices were additionally used to provide point of operation vending services for photocopiers.
Although print, scan, and faxing services have been added to copiers over the years, the basic interface to these FDI devices has not changed. Consequently, FDI devices have limited capability to effectively track non-copy jobs on Multi-Function Devices (MFDs). Thus, for example, FDI devices cannot charge different rates for print versus scan jobs and do not adequately support the job based charges that are required for scan jobs.
Furthermore, due to the limited information that can be passed to FDI devices through this interface, there are limited opportunities to charge premiums for job execution based upon the consumables used on the job (e.g., transparencies, label stock) or job programming attributes (e.g., n-up).
In the past, certain classes of jobs could not be accounted for (e.g., scan jobs) and the functionality of hardware signals on the FDI had to be modified based on the functionality available on the device (e.g., the large/small paper signal would be used for color or black & white impression).